Specific Gravity at 15° C.
Refracto-metric Degree at
1 40° C.
Insect wax ,
Carnauba wax .
Japan wax .
• — •
Tallow . . .
I • TOO
Solid paraffin .
This is obtained from wool by washing with soap or alkali carbonate
solution or by extracting with a solvent (carbon disulphide or benzine).
The crude fat is utilised especially for the preparation of lanoline and
distilled wool fat, from which wool fat oleine and stearine are prepared.
The latter products are" dealt with in the next chapter (Industrial Products
from the Treatment of Fatty Matters) ; here we shall deal only with crude
and purified wool fat and lanoline.
A. Crude Wool Fat
This has a tallowy consistency, a yellow or brown colour, and a peculiar,
disgusting odour. It is slightly soluble in alcohol, and more so in ether,
chloroform, benzene, etc.; it saponifies with difficulty. Its physical and
chemical characters are given later in Table XLIX, dealing with animal
waxes. It is dextro-rotatory ([a]-*0 = about 6-9° in chloroform solution),
and its acid number may vary from about 10 to 50 (5-25% of free acids
calculated as oleic acid) according to the method used in its extraction.
On calcination it leaves little ash (1-5%).
' It contains marked quantities of unsaponifiable substances (40-50%),
consisting mainly of cholesterol and isocholesterol, and consequently gives
the reaction of these higher alcohols with chloroform and sulphuric acid
(see General Methods, 19, i, Higher Alcohols). It may also contain water
and various foreign impurities in varying quantities.
Crude wool fat is readily identified by its external characters and by
the cholesterol reaction. In analysing it, it is usually sufficient to determine
the content of water, extraneous impurities, and ash, with possibly the
acid number and the unsaponifiable matter, by the usual methods (see
B. Purified Wool Fat (Lanoline)
Purified wool fat is pale yellow and sticky, has a faint, peculiar smell
and the consistency of an ointment and undergoes little change in the air.gin wax are-compared with those of the substances most usually